Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) narrates that the Prophet (peace and blessings be upon him) said: "Every child that is born is born upon the fitrah (natural disposition) until he begins to speak (that is, until he reaches maturity). When he begins to speak, he is either grateful or disbelieving."
Ahmad recorded it; its chain contains Abu Ja'far al-Razi, who is thiqah (trustworthy), though there is disagreement about him, and the remaining narrators of this report are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب القدر / 11946
Hadith Gradingمحدثین:إسنادہ حسن
Hadith Takhrij«اخرجه احمد فى المسند (353/3) ، أخرجه مسند أحمد برقم: 14391»